That is truly weird. My original equipment (G4 400 AGP) Quantum 9 gig as well as my 1.5 year old Maxtor 40 gig both show S.M.A.R.T. status as verified.

From the online help:
Most disk drives include S.M.A.R.T. hardware developed by IBM that allows hard disks to test themselves for potential problems. You can check the health of your hard disk in Disk Utility, located in Applications/Utilities.

If you've been having some problems with your computer, it's a good idea to check the status of the hard disk.

To check the status of a disk:

Open Disk Utility, located in Applications/Utilities, and select the disk in the left column. Look at the bottom of the window to see the S.M.A.R.T. status.

If your disk is "verified," it's a valid disk with nothing wrong at this time. If you see "About to Fail" in red letters, back up your disk immediately and have the disk replaced. It will fail.